A ONE-STEP SANDWICH ENZYME-IMMUNOASSAY FOR HUMAN MATRIX METALLOPROTEINASE-8 (NEUTROPHIL COLLAGENASE) USING MONOCLONAL-ANTIBODIES

A one-step sandwich enzyme immunoassay (EIA) system for human matrix m etalloproteinase 8 (MMP-8, neutrophil collagenase, EC 3.4.24.7) has be en established with a pair of monoclonal antibodies prepared against t he zymogen of MMP-8 purified from human neutrophils. MMP-8 in samples simultaneously reacted with both solid-phase and peroxidase-labeled an tibodies, Sensitivity of this EIA system was 0.34 mu g/l (5.7 pg/assay ) and linearity was obtained between 0.5 and 500 mu g/l (8.3-8300 pg/a ssay). The EIA system recognized both precursor and active forms of MM P-8 but not MMP-8 complexed with tissue inhibitors of metalloproteinas es, There was no difference in the MMP-8 levels between the plasma sam ples from patients with rheumatoid arthritis or osteoarthritis and tho se from healthy subjects (median 6.2 mu g/l, range 1.5-28 mu g/l). How ever, the level in synovial fluids from patients with rheumatoid arthr itis (median 345 mu g/l, range 84-2860 mu g/l) was shown to be higher than that from osteoarthritic patients, MMP-8 levels in human whole sa liva from patients with periodontal diseases (median 282 mu g/l, range 0-1420 mu g/l) were also significantly higher than those from clinica lly healthy subjects (median 25 mu g/l, range 0-100 mu g/l). Immunorea ctivity analyses showed that MMP-8 species in normal human plasma exis ts as a precursor but not as a complex form with tissue inhibitor of m etalloproteinases (TIMP)-1 or TIMP-2.